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The creation of new sunflower hybrids with high genetic potential for seed yield on the basis of interspecies hybridization requires a possession of the information about the mode of inheritance and the combining abilities of the created inbreed lines for the total seed number per head and the mass of 100 seeds. Apart from this the research of interdependence between yield components and seed yield allows the defining of traits which have the biggest influence on the yield formation. Significant differences were found among the A lines, Rf testers and their F1 hybrids in total seed number per head and the mass of 100 seeds. Analysis of variance of the combining abilities revealed highly significant differences for GCA and SCA. Highly significant positive value GCA was demonstrated by A-line NS-GS-5 for both traits. Hybrid NS-GS-5xRHA-R- PL-2/1 has the highest significant value SCA for both traits. The main role in inheritance of the total seed number per head and the mass of 100 seeds is played by non additive component of the genetic variance which is confirmed by the GCA/SCA relation in F1 generation that is less than one (0.11, 0.24). Rf-testers had the highest average contribution in the expression of the total seed number per head (55.8%) while for the mass of 100 seeds a more significant contribution was given by A-line (70.6%). A strong positive interdependence has been determined between seed yield and total seed number per head (0.376*) and a very strong positive interdependence was determined between seed yield and the mass of 100 seeds (0.823). These research can be significant for the creation of new high-yielding sunflower hybrids on the basis of interspecies hybridization. Stvaranje novih hibrida suncokreta sa visokim genetskim potencijalom za prinos semena na osnovu interspecijes hibridizacije zahteva posedovanje informacija o načinu nasleđivanja i kombinacionim sposobnostima stvorenih inbred linija za ukupan broj semena po glavi i masu 100 semena. Pored ovoga, istraživanja međuzavisnosti komponenti prinosa i prinosa semena omogućavaju definisanjae svojstava koja imaju najveći uticaj na formiranje prinosa. Pronađene su značajne razlike između A linija, Rf testera i njihovih F1 hibrida u ukupnom broju semena po glavi i masi od 100 semena. Analizom varijanse kombinacionih sposobnosti uočene su visoko značajne razlike za OKS i PKS. Visoko značajnu pozitivnu vrednost OKS pokazala je A-linija NS-GS-5 za obe ispitivane osobine. Hibrid NS-GS-5xRHA-R-PL-2/1 ima visoko značajnu vrednost PKS za ukupan broj semena po glavi i masu 100 semena. Glavnu ulogu u nasleđivanju ukupnog broja semena po glavi i mase 100 semena igra neaditivna komponenta genetske varijanse, što je potvrđeno odnosom OKS/PKS u F1 generaciji koji je manji od 1 (0.11, 0.24). Najveći prosečan doprinos u ekspresiji ukupnog broja semena po glavi (55.8%) imali su Rf testeri, dok je za masu od 100 semena mnogo važniji doprinos A-linija (70.6%). Jaka pozitivna međuzavisnost utvrđena je između prinosa semena i ukupnog broja semena po glavi (0.376*) i vrlo jaka pozitivna međuzavisnost utvrđena je između prinosa semena i mase 100 semena (0.823). Ova istraživanja mogu biti značajna za stvaranje novih visoko prinosnih hibrida suncokreta na bazi interspecijes hibridizacije.

For much of the past century, mutagenesis has gained popularity in plant genetics research as a means of inducing novel genetic variation. Induced mutations have been applied for the past 40 years to produce mutant cultivars in sunflower by changing plant characteristics that significantly increase plant yield and quality. The present study is focused on generating baseline data to elucidate the role of genotypic differences in the response of sunflower to induced mutagenesis with the aim of expanding the applicability of the use of induced mutant stocks in the genetic improvement of the crop and in its functional genomics. The strategy adopted was to estimate the optimal treatment conditions (doses of mutagens) through relating the extent of damage in seedling progeny to the exposure levels of the initiating propagates to mutagens. Seeds of fifteen elite sunflower genotypes of commonly used as breeding stocks and grown on commercial scales were treated with a range of mutagens: gamma rays (γ rays); fast neutrons and with ethyl-methane-sulphonate (EMS) at different treatment doses. The three mutagenic agents affected seedling height, reducing it with increasing dosage. Based on the mutagen damage on seedling height, the 50% and 30% damage indices (D50 and D30, respectively) were estimated for the 15 sunflower genotypes for the three mutagens. The D50 (D30) values for the sunflower lines ranged from 120 to 325 Gy (5 to 207 Gy) for gamma irradiation; 9 to 21 Gy (0.1 to 10 Gy) for fast neutrons and 0.69 to 1.55% (0.01 to 0.68%) concentration of EMS.

The sunflower is one of the four most important oilseed crops in the world, and the nutritional quality of its edible oil ranks among the best vegetable oils in cultivation. Typically up to 90% of the fatty acids in conventional sunflower oil are unsaturated, namely oleic (C 18:1, 16%–19%) and linoleic (C 18:2, 68%–72%) fatty acids. Palmitic (C 16:0, 6%), stearic (C 18:0, 5%), and minor amounts of myristic (C 14:0), myristoleic (C 14:1), palmitoleic (C 16:1), arachidic (C 20:0), behenic (C 22:0), and other fatty acids account for the remaining 10%. Advances in modern genetics, most importantly induced mutations, have altered the fatty acid composition of sunflower oil to a significant extent. Treating sunflower seeds with γ- and X-rays has produced mutants with 25%–30% palmitic acid. Sunflower seed treatment with X-rays has also resulted in mutants having 30% palmitoleic acid, while treatments with mutagenic sodium azide have produced seeds containing 35% stearic acid. The most important mutations have been obtained by treatment with dimethyl sulfate, which produced genotypes with more than 90% oleic acid. Mutants have also been obtained that have a high linoleic acid content (>80%) by treating seeds with X-rays and ethyl methanesulfonate. Of the vitamin E family of compounds, sunflower oil is known to predominantly contain α-tocopherol (>90%). Spontaneous mutations controlled by recessive genes have been discovered that significantly alter tocopherol forms and levels. The genes in question are tph1 (50% α- and 50% β-tocopherol), tph2 (0%–5% α- and 95%–100% γ-tocopherol), and tph1tph2 (8%–40% α-, 0%–25% β-, 25%–84% γ-, and 8%–50% δ-tocopherol). The existence of (mutant) genes for increased levels of individual fatty acids and for different forms and levels of tocopherol enables the development of sunflower hybrids with different oil quality. The greatest progress has been made in developing high-oleic hybrids (>90% oleic acid). There has been considerable work done recently on the development of high-oleic hybrids with altered tocopherol levels, the oil of which will have 10–20 times greater oxidative stability than that of conventional sunflower oil. While sunflower breeders work on developing hybrids with altered oil quality, medical scientists in general and nutritionists in particular will determine the parameters for the use of these novel types of oil that can improve human nutrition and be used in the prevention of cardiovascular diseases.

Due to a specific structure of its main organs (root, stem, leaves, and head), sunflower can be successfully grown on marginal soils and in semiarid conditions, and it is more resist‐ ant to abiotic stresses, than other field crops. Unfortunately, it is very sensitive to biotic stresses. In sunflower breeding for resistance to abiotic stresses, the greatest progress has been made in selection for drought resistance. Breeders use over 30 different parameters in sunflower screening for drought resistance, with physiological ones being the predomi‐ nant type. The best breeding results have been achieved using the phenomenon of staygreen, with the added bonus that this method incorporates into the cultivated sunflower not only drought resistance but resistance to Macrophomina and Phomopsis as well. The di‐ versity of the wild Helianthus species offers great possibilities for increasing the genetic resistance of the cultivated sunflower toward abiotic stresses. In using wild sunflower species in sunflower breeding for drought resistance and resistance to salinity, best re‐ sults have so far been achieved with H. argophyllus and H. paradoxus, respectively. In ad‐ dition to the use of wild Helianthus species, sunflower breeding for abiotic stress resistance should also make more use of molecular breeding techniques. More progress has been made in sunflower breeding for heat resistance than in that for cold resistance. Specific breeding programs dealing with sunflower resistance to mineral deficiency and mineral toxicity have yet to be established. Concerning biotic stresses, the main problem in sunflower cultivation is caused by fungal diseases. Genetic variability of cultivated sunflower is very low and deficient in diseaseresistance genes. Due to wild sunflower species of the Helianthus genus, genes that con‐ fer resistance to certain diseases were discovered and incorporated into the genotypes of the cultivated sunflower. Based on the wild species, genes were found that confer resist‐ ance to Plasmopara halstedii, Puccinia helianthi, Verticillium dahliae, V. albo-atrum, and Erysi‐ phe cichoracearum. Furthermore, wild sunflower species provide a high level of tolerance (field resistance) to Phomopsis/Diaporthe helianthi, Macrophomina phaseolina, Albugo erago‐ pognis, and Alternaria ssp. Sources of resistance to other harmful diseases are sought after within wild sunflower species. © 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. With the use of one wild species of H. annuus from Kansas (USA.), genes conferring re‐ sistance to a group of imidazolinone (IMI) or sulfonylurea herbicides were discovered. Moreover, similar genes were found through induced mutations. These sources of resist‐ ance provide successful control over a broad spectrum of weeds, which infest sunflower crops, including broomrape. The growth of the parasitic weed sunflower broomrape (Orobanche cumana Wallr) is a ma‐ jor issue in sunflower production, especially in Central and Eastern Europe, as well as in Spain. Six races of broomrape have been detected (A, B, C, D, E, and F) and dominant resistance genes (Or1, Or2, Or3, Or4, Or4, and Or6) were found in wild sunflower species. During the last 4–10 years, new virulent races of broomrape emerged in several European countries. Geneticists and breeders work on finding the sources of resistance to the new broomrape races in wild sunflower species. Numerous insect species cause economic damages during sunflower production, espe‐ cially in North America (the homeland of sunflower). Homoeosoma species are the most widespread insects that infest sunflower. Homoeosoma nebulella infests sunflower in Eu‐ rope and Asia, while infestation with H. electellum poses a major problem in USA, Cana‐ da, and Mexico. Based on the use of wild sunflower species H. tuberosus, genes conferring resistance to Homoeosoma species were incorporated. Sunflower has an armored layer in the hull, which provides resistance to this insect. Sources of resistance to other economi‐ cally harmful insects are sought after. New methods in biotechnology, particularly marker genes, have been frequently used in breeding for abiotic and biotic stresses.

SUMMARY The aim of this work was the application of previously developed and development of new PCR markers for the evaluation of sunflower resistance to downy mildew. Twenty sunflower inbred lines were investigated. Plant resistance to downy mildew was determined by the whole seedling immersion method. Genomic DNA was extracted from the first pair of leaves, and its polymorphism was investigated by RAPD, SSR and several published markers for disease resistance. The presence of the markers Ha-NBS 7/R, Ha-NBS 8/R, Ha-NBS 9/R, in Pl6 donor lines (Ha-335, JM-8) and in resistant progeny (Ha-26, G12, G10, G11) confirm that HAP3 could be useful for the detection of the Pl6 gene. DNA polymorphism, which coincided with disease resistance, was revealed with one RAPD (UBC 119 fragment 900-1000 bp) and one SSR primer (ORS37 fragment 600-700 bp). Amplified fragments segregated in the same way, i.e., they appeared in 50% of the resistant genotypes. The non-expecting SSR fragment was purified, cloned and sequenced. The results indicated that this fragment is not a part of a coding sequence. Specific primers for the amplification of this fragment have been designed and the investigation of the inheritance of this SCAR marker is under way. None of the applied markers appeared in all resistant genotypes. In order to select lines for making crosses for use in further investigation, the obtained results were also used for the calculation of genetic distances between genotypes (simple matching coefficient) and the construction of a dendrogram (UPGMA method).

The main goals of sunflower breeding in Yugoslavia and abroad are increased seed yield and oil content per unit area and increased resistance to diseases, insects and stress conditions via an optimization of plant architecture. In order to determine the mode of inheritance, gene effects and correlations of total leaf number per plant, total leaf area and plant height, six genetically divergent inbred lines of sunflower were subjected to half diallel crosses. Significant differences in mean values of all the traits were found in the F1 and F2 generations. Additive gene effects were more important in the inheritance of total leaf number per plant and plant height, while in the case of total leaf area per plant the nonadditive ones were more important looking at all the combinations in the F1 and F2 generations. The average degree of dominance (Hi/D)1/2 was lower than one for total leaf number per plant and plant height, so the mode of inheritance was partial dominance, while with total leaf area the value was higher than one, indicating super dominance as the mode of inheritance. Significant positive correlation was found: between total leaf area per plant and total leaf number per plant (0.285*) and plant height (0.278*). The results of the study are of importance for further sunflower breeding work. Oplemenjivanje suncokreta u svetu i kod nas usmereno je na povećanje prinosa semena i sadržaja ulja po jedinici površine, otpornosti prema bolestima insektima i stresnim. uslovima optimalizacijom arhitekture biljke. U cilju utvrđivanja načina nasleđivanja, efekta gena i međuzavisnosti ukupnog broja listova po biljci, ukupne lisne površine po biljci i visine biljke, izvršena su dialelna ukrštanja isključujući recipročna sa šest genetski divergentnih inbred linija suncokreta. Dobijene su signifikantne razlike u srednjim vrednostima za sva ispitivana svojstva F1 i F2 generaciji. Aditivni efekat gena je bio od većeg značaja u nasleđivanju ukupnog broja listova po biljci i visini biljke dok je neaditivni efekat gena bio značajniji kod ukupne lisne površine po biljci uzevši u obzir sve kombinacije ukrštanja u F1 i F2 generaciji. Prosečan stepen dominacije (H1/D)1/2 je kod ukupnog broja listova po biljci i visine biljke manji od jedinice iz toga se može zaključiti da je način nasleđivanja parcijalna dominacija, a kod ukupne lisne površine je veći od jedinice što ukazuje na superdominaciju. Značajna pozitivna međuzavisnost ustanovljena je između ukupne lisne površine po biljci i ukupnog broja listova po biljci (0.285*), visine biljke (0.278*). Rezultati ovih istraživanja imaće značaja u daljem radu na oplemenjivanju suncokreta.

The hexaploid species of Helianthus tuberosus is a potential source of resistance to several sunflower pathogens. But crossed with cultivated sunflower, it produces F, hybrids which have low values of fertility or even full sterility. Pollen viability and meiotic features were studied in 17 populations of the species H. tuberosus and in F1 hybrids. Significant differences in pollen viability existed between populations (47.1–98.8%). In the 15 FI hybrids, plant fertility ranged from 0 to 100 per combination, while pollen viability ranged from 12.4 to 57.1. Meiosis was almost normal in the analyzed species, and irregular in the F, hybrids. The highest percentage of meiocytes was with bivalents (85.9), but univalents (0.3) and multivalents (13.8) occurred as well. In metaphase and anaphase, the percentage of meiocytes with fast and lagging chromosomes was high. In anaphase, chromosome bridges were detected in 9.9 of the meiocytes.

Path coefficient analysis was used to separate direct and indirect effects of studied traits on seed oil content and seed yield, and to identify traits that could be used as selection criteria in sunflower breeding. Significant and highly significant correlations were found between most of the examined traits. Highly significant negative correlations have been established between stem diameter, total leaf area per plant, head diameter and 1,000-seed weight on one side and seed oil content on the other. Highly significant positive correlations have been established between seed yield on one side and stem diameter, total leaf area per plant, head diameter, total number of seeds per head, and the 1,000-seed weight on the other. The weight of 1,000 seeds had a highly significant direct negative effect on seed oil content and a highly significant direct positive effect on seed yield. The total number of seeds per head has demonstrated a highly significant direct positive effect on seed yield and oil content. The total leaf number per plant has demonstrated a significant direct positive effect on seed yield. A path coefficient analysis of seed yield at phenotypic level indicated that maximum direct effects were shownby the weight of 1,000 seeds, total number of seeds per head and total leaf number per plant. The total number of seeds per head was the most important trait that determined seed yield and oil content. The obtained results can be used in sunflower breeding programs aimed at the development of sunflower hybrids that combine high genetic potentials for seed yield and seed oil content.

Sunflower (Helianthus annuus L.) is among the most important oil crops in the world. Due to its low to moderate production requirements, high oil quality, protein content, and utilization of all plant parts, it is grown on about 14 million ha. The major sunflower-producing countries in the world are the Soviet Union, Argentina, China, the United States, France, Spain, Romania, Turkey and Hungary. Sunflower became an oil crop around the end of the 19th century, when ‘popular selection’ was practiced in several parts of Russia to improve sunflower populations grown at that time. The most important contributions to the development of sunflower were made by Pustovoit and Jdanov in the Soviet Union, who increased the oil concentration in sunflower seed above 500 g kg−1. Leclercq of France discovered the first usable sourccytoplasmic male sterility in a cross H. petiolaris Nutt. × H. annuus L. and Kinman of the United States developed fertility restorer lines RHA 265 and RHA 266 which allowed practical development of sunflower hybrids. When starting a breeding program, it is useful to design a model of the desired hybrid and then strive to develop the envisaged model as closely as possible. It is also advisable to direct breeding efforts toward a limited number of economically important traits. These should include: (1) components of seed and oil yield: the number of seeds per plant, test weight, 1000-seed weight, low husk content and high oil concentration in the seed; (2) architecture of the sunflower plant: plant height, head size and shape, angle of the head, leaf area and leaf canopy; (3) increased harvest index: oil quality, protein concentration and quality, early maturation, short stem and uniform height; and (4) resistance to diseases and drought using wild sunflower species. Mass selection, a method of selecting desirable plants from a population on the basis of phenotypic traits, is still in effective method in sunflower breeding. Recurrent selection appears to be a promising method of increasing the frequency of desirable genotypes in a source population. Genetic variability of the cultivated sunflower may be increased by interspecific hybridization with wild sunflower species. The inclusion of wild species programs is difficult because of differences in chromosome number (2n, 4n, 6n) and incompatibility. These obstacles have been overcome by embryo culture and other tissue culture techniques. Generally, the use of new technologies in sunflower breeding is imperative, particularly in regard to the introduction of resistance genes to diseases and insect pests.

The cultivated sunflower (Helianthus annuus L.) is one of most important oil crops of the world. Although sunflower is primarily grown for extraction of its seed oil there is a limited production of non-oilseed sunflower types which are used in confections industry or as bird feed. The objective of this research was development of hybrids with high and stable oleic acid content and modified tocopherol composition, with high values for the two most important agronomic characters (seed yield and oil yield) and high tolerance to Phomopsis. The incorporation of the gene Ol+tph1 into these genotypes has led to the development of high-oleic hybrids with altered tocopherol profiles. Oil of these hybrids has a much longer shelf-life than standard sunflower oil. The process of incorporating the genes Ol+tph2 and Ol+tph1tph2 into highly productive sunflower genotypes is under way. The most important results of this line of research are the newly developed female lines with the oleic acid content in oil over 90% and the male lines (restorers) with an oleic acid content in the 89-93% range. Using these lines, hybrids will be developed whose oleic acid content in oil will exceed 90%.

The sunflower is one of the four most important oil crops in the world. The common sunflower oil predominantly contains linoleic acid, followed by oleic, palmitic and stearic ones as well as some others that are found only in traces. As far as tocopherols are concerned, the predominant type are alpha tocopherols. Using sources for a high oleic acid content (Ol genes) and sources with genes tph1 (50% alpha + 50% beta tocoph.), tph2 (0–5% alpha + 95–100% gamma), and tph1tph2 (8–40% alpha + 0–25% beta + 25–84% gamma + 8–10% delta), the highly Phompsis-tolerant parental lines of the hybrids NS-H-45, NS-H-626, and NS-H-680 were translated into three isogenic forms. These have taken the following forms: a) Ol+tph1; b) 01+tph2; and c) 01+tph1tph2. In other words, three types of high-oleic oil with different tocopherol type and content have been obtained. Besides these isogenic lines, a number of oleic and linoleic B-lines with a different tocopherol composition have been developed as well. Also, we have developed a large number of high-oleic, high-oil restorer lines with different tocopherols. Some of these have a high level of tolerance to Phomopsis. The newly developed B- and Rf-lines can be used to develop new hybrids with different oil quality. Due to a synergy between Ol and tph genes, the oil oxistability of these new hybrids can be up to 20 times higher than in the common sunflower oil.